Various methods which store large quantity of data in various storage environments such as a cloud, and a server device and synchronize the data with a personal terminal device are widely used. For example, in the case of a delta synchronization (delta sync) method, when changed contents of a file which has been stored in a terminal device is synchronized with the server, only changed blocks of the file, instead of the entire file, are transmitted, thereby minimizing a time for synchronization.
Technologies such as metadata synchronization meta sync) or deduplication synchronization (deduplication sync) are widely utilized.
However, various synchronizing methods of the related art independently exist for every function, but there is no combined synchronizing method, so that all of the advantages of individual synchronizing methods may not be fully utilized.